Head mounted or generally wearable image projection systems are used for providing virtual and/or augmented reality experience by displaying images directly into users' eyes. Various types of head mounted projection systems are known utilizing image projection in front of or into the eyes of a user. Such projection systems are in many cases configured as glasses mountable onto a user's head and operable for projecting images onto the user's eyes for providing true and convincing display.
Similar to standard display systems, head mounted display systems aim to provide high resolution images while utilizing limited computational power. To simplify image rendering complexity, certain retinal/foveal display systems have been developed, utilizing separate image projections for the foveal region of the user's eye, and an additional, lower resolution image projection directed to the peripheral regions of the retina to provide a wide field of view.
US2008002262 discloses a head mounted display device which has a mount which attaches the device to a user's head, a beam-splitter attached to the mount with movement devices, an image projector which projects images onto the beam-splitter, an eye-tracker which tracks a user's eye's gaze, and one or more processors. The device uses the eye tracker and movement devices, along with an optional head-tracker, to move the beam-splitter about the center of the eye's rotation, keeping the beam-splitter in the eye's direct line-of-sight. The user simultaneously views the image and the environment behind the image. A second beam-splitter, eye-tracker, and projector can be used on the user's other eye to create a stereoptic, virtual environment. The display can correspond to the revolving ability of the human eye. The invention presets a high-resolution image wherever the user looks.
US 2012/0105310 describes a head mounted display system with at least one retinal display unit having a curved reflector positioned in front of one eye or both eyes of a wearer. The unit includes a first set of three modulated visible-light lasers co-aligned and adapted to provide a laser beam with selectable color and a first scanner unit providing both horizontal and vertical scanning of the laser beam across a portion of the curved reflector in directions so as to produce a reflection of the color laser beam through the pupil of the eye onto a portion of the retina large enough to encompass the fovea. The unit also includes a second set of three modulated visible-light lasers plus an infrared laser, all lasers being co-aligned and adapted to provide a color and infrared peripheral view laser beam, and a second scanner unit providing both horizontal and vertical scanning of the visible light and infrared laser beams across a portion of the curved reflector in directions so as to produce a reflection of the scanned color and infrared laser beams through the pupil of the eye onto a portion of retina corresponding to a field of view of at least 30 degrees×30 degrees.
US 2005/185281 describes an apparatus for viewing which includes a screen. The apparatus includes means for detecting a fixation point of a viewer's eyes on an image on the screen. The apparatus includes means for displaying a foveal inset image of the image on the screen about the fixation point so a viewer's fovea sees the foveal image while the rest of the eye sees the image. The method includes the steps of detecting a fixation point of a viewer's eyes on an image on a screen. There is the step of displaying a foveal inset image of the image on the screen about the fixation point so the viewer's fovea sees the foveal image while the rest of the eye sees the image.
US 2009/189830 describes a display device which is mounted on and/or inside the eye. The eye mounted display contains multiple sub-displays, each of which projects light to different retinal positions within a portion of the retina corresponding to the sub-display. The projected light propagates through the pupil but does not fill the entire pupil. In this way, multiple sub-displays can project their light onto the relevant portion of the retina. Moving from the pupil to the cornea, the projection of the pupil onto the cornea will be referred to as the corneal aperture. The projected light propagates through less than the full corneal aperture. The sub-displays use spatial multiplexing at the corneal surface.